Painting Question

[BuzzerMan]

So i'm a pretty decent painter imo.

I'm just having trouble grasping how to feather/blend.
I.e to make a color blend out with that which is beneath it to make it not so rigid and more of a natural look to it.

Tips on this or link to guides about such would be really apreciated :)

[CanaBalistic]

I found this... wow, shock and aww
http://www.spikedhumor.com/articles/27674/Amazing_Spray_Paint_Artist.html

This was pretty cool, nothing about feathering though
http://www.p2pays.org/ref/01/00777/appltech.htm

Sorry i couldnt have been more help